With regard to this description and the subsequent claims, the expression “acquisition of optical information” is meant to indicate the acquisition of information concerning an object (for example, distance, volume, footprint, its identifying data, or its characteristics) by means of the acquisition and elaboration of a diffuse light signal emanating from the same object. The expression: “optical information” is used in the broadest sense and includes optical codes, but also, more generally, images containing suitable characteristics for the identification and/or selection of an object, for example, on the basis of its shape and/or volume.
With the expression: “optical code”, is meant to indicate any graphical representation that has the function of storing encoded information. A particular example of an optical code consists in linear or two-dimensional codes, in which information is encoded by using appropriate combinations of fixed shape elements, for example square, rectangular or hexagonal, of a dark color (usually black) separated by light elements (spaces, usually whites), such as bar codes, stacked codes and bi-dimensional codes generally, color codes, etc. The expression “optical code” also includes, more generally, other graphical forms with an information encoding function including clearly printed characters (letters, numbers, etc.) and forms (“pattern”) details (such as stamps, logos, signatures, fingerprints, etc.). The expression “optical code” also includes detectable graphical representations, not only in the visible light field but also in the range of wavelengths between infrared and ultraviolet.
For ease of discussion, in the following text explicit reference will be made to optical code readers (commonly referred to as: scanners) as examples relating to the implementation of this invention. The invention does however find application in other optical information acquisition devices such as optical image sensors (vision sensors, smart cameras) for the recognition of objects by means of detecting their features regarding shape or dimensions, and generally for artificial vision applications such as object quality control in industrial processes.
The optical information acquisition device of the present invention finds a preferred application within all systems wherein an array of objects is to be sorted quickly and effectively, such as for example motorized product storage systems or in the field of transport. In such circumstances, the scanner is placed in a fixed position near a conveyor belt upon which are placed the objects to be sorted and the sorting is carried out based upon the reading of an optical code printed on a label associated with each object.
The scanner typically comprises a main body that contains all of the devices necessary for the detection and reading of the optical code, and a power connector associated with the main body for the electrical supply of the above-mentioned devices and the transfer of input/output data to/from the scanner.
In those cases where the scanner is designed to be installed within a local area network (LAN), in addition to the above-mentioned power connector (which in this case may not be used for data transfer) the scanner includes a connector for transferring data to and from the network (in particular an Ethernet connector). The Ethernet connector is associated with the main body near to the power connector. These scanners are also indicated below by the expression “scanner with a dual connector”.
Scanners with dual connectors are available on the market wherein the power connector and the Ethernet connector are part of a connector assembly that can be swiveled with respect to the main body. In particular, the connector assembly can be rotated with respect to the main body between an initial operating position wherein said connectors extend substantially perpendicularly to one side face of the main body and a second operating position wherein said connectors extend substantially perpendicularly to a rear face of the main body.
The scanners described above allow the connectors to be positioned most appropriately, between said two operating positions depending upon the space available within the scanner installation area corresponding to one of the said faces and/or the orientation of the external cables to be connected to the scanner. In particular this scanner allows for the wiring of the scanner (i.e. the connection of external cables to the respective scanner connectors) at that face of the scanner that has the greatest freedom of action and/or without the necessity to excessively bend the aforesaid cables.
It is known that a plurality of scanners that are connected in series to each other can then be connected to a LAN, this in order to combine the information read from each of said scanners.
In this case, the first scanner in the series (scanner Master) is connected to a programmable logic controller (PLC) or a host PC, while the other scanners in the series (scanner Slave) are each connected to a respective shunt device having an input connector for the cable upstream of the series, an output connector for the cable downstream of the series, a first power connector for supplying power to the shunt device and a second power connector for supplying power to the respective scanner Slave. The shunt device output connector connected to the last scanner Slave of the series is connected to a termination.
The Applicant has noted that the creation of a network of scanners of the type described above, necessarily requires, other than the installation of the scanners themselves, the installation of the aforesaid shunt devices which is quite expensive.